Pump



March 2, 1943. l. c. JENNINGs 2,312,837

PUMP

Fild Dec. 20, 1939 l 3 Shee-bs-Sheet 2 h u g m, n b 04 w o Pr 5 @I J H 0 U w Tg m x Q @l J n g s M L? IVVENTO/i [RV/.NG C! JENA/[NGS By @Mw @.M

)mum/sys Mareh 2, 1943.

l l. c. JENNINGs PUMP Filed Dec. 20. 1939 1- 3 Sheets-Sheet 3,

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PatentedlMar. 2, 1943 UNITED STATES PATENT oFEicE 2m? I '1i-vm: c. Jenninzs, south Norwalk, conn.`

Application December 20, 1939, Serial No. 310,218

In Great Britain December 21, 1938 (CL 23o-79) lclaims.

This invention is directed to fluid piston pumps or compressors, and more particularly to hydroturbinepumps of the type employing a rotating water or other liquid ring as a pumping or displacing medium, in which the liquid of the ring -and developments in the pump described in my co-pending application, Serial No. 56,815, illed December 30;'1935, for Pump, and patented as No. 2,195,1'14-,on March 26, 1940, wherein is illustrated a circular rotor operating within an eccentric casing, the rotor being revoluble upon port members, preferably tapered or conical, extending within side portions of the revolving rotor. This invention is not limited specifically to this type of pump, reference being made thereto for illustrative purposes. Pumps vof this nature have been found very satisfactory inthe handiing of air and gas, and they will also handle denser fluids.

In pumps of this character, it is u'sal to mount the rotor in an integral cylindrical casing having conical or cylindrical .port members functioning as hub members for the rotor, and vpositioned in separate, annular cylinder heads or ends` When it is desired to dismount such pumps for inspection or repair, these heads and yport members have to be removed axially, and therefore, cannot be inspected in assembled relation to the casing.

Accordingly, it is an object,of the present invention to provide an arrangement whereby inspection or repair is facilitated, and withdrawal of the port members rendered unnecessary for thepurpose of securing access to the rotor chamber.' A further object is to provide complete accessibility without need for removing gaskets and bolts -which secure the heads in position.

The invention contemplates the use of a lobe heads. and the lobe casing between the cone heads. being split horizontally, provides a removable section which thereby functions as a lobecover. a y

From a structural standpoint, the split casing, and the conical port members having integral head or end sections, will be assembled such that the peripheryl of the head sections will preferably be embracedl by the casing. To this end, the heads maybe provided with an annular ilange or shoulder adjacent the end faces of the casing body, but secured by bolts or screws over the lower. half only of the circumference of the casing, and may be'provided with suitable gaskets over abutting surfaces throughout that portion of the body of the casing to which the heads are secured, thus facilitating removal of the upper portion of the casing and avoiding distortion of the structure.

This structural arrangement takes into consideration an important feature of the invention,

- in that the flanges' forming the periphery of the cover which may be removed for inspection purhead or end members may be bolted against shims or gaskets at the bottom half of the casing, making possible longitudinal adjustment at initial assembly and to take up wear, and when the upper half of the lobe casing is removed, to allow measuring the clearances. This design provides larger areas for inlet and discharge passages, shortens the' shaft length, reduces the cost of manu` facture, and forms a much stiffer structure.

Still another object of the invention is the utilization of an improved sealing means associated with the rotor which, while alfording a satisfactory sealing against outward and inward leakage, will also avoid clogging of the parts under circumstances when the 7pump is used for fiber-,V

. laden fluids, such as paper making stock, or the like.

.A` feature of the invention in this connection resides in the provision of annular side plates upon the rotor having wide edges, and spaced away from the internal surfaces of the head sections -to provide a chamber in which liquid under pressure may be introduced for sealing purposes and for flushing the clearances to avoid choking when the ,pump is used for such liber laden fluids.

The invention also has for an object the provision of an improved mechanical seal or sealing packing about the rotor shaft inwardly of the axial bearings of the rotor, and the inclusion of means facilitating the removal of the bearings from the rotor shaft. i

Another object of the invention is to provide a horizontally spli -case pump, the lobe casing ot objects which will appear as the description prof ceeds, reference may be made to the accompanying drawings, in which:

Fig. 1 is an irregular, longitudinal section through the pump, the left -half of which is taken on the line I-I of-Fig. 3, and the right half of which is taken on the line Iii-Ia of Fig. 2;

Fig. 2 is a cross section taken on the line 2-2 of Fig. 1;

Fig. 3 is cross section taken on the line 3-3 of Fig. 1;

Fig. 4 is a detailed sectional view of the structure shown in the lower left corner of Fig. 1, but illustrating a modification for recirculating sealing liquid from the lower part of the pump casing, which is then used as a separator;

Fig. 5 is an enlarged section, with certain parts shown in elevation, illustrating details of the shaft bearing, bearing mounting, and mechanical seal; and

Fig. 6 is a longitudinal section taken on the line 6 6 of Fig. 2, through ports provided in the bottom lobe to allow the removal ofsealing liquid, for unloading purposes.

In the operation cf these compressors or pumps, the liquid ring rotated by the rotor, follows an operating path defined by the eccentric internal contour of the Casing best illustrated in Fig. 2. The liquid ring first recedes from the buckets approach the-minor axes, -or lands between the lobes of the casing, theoperating ,liq-

vuid `ring is forced inward, into the buckets, to

This .action 1 'perform its compression .stroke- Inay'take place several times during a single revo- -lutionof the rotor,l depending iupon the number :of lobes formed in vthe pump casing. In theV vlpresent illustration two lobes are illustrated, `sep- Iarated from each other by lands at the ends of the minor axis of the eccentric casing.

Since the construction and operation of `this type of pump are well known, and -fully described in my co-pending application, above noted, it is `not necessary to go into the details thereof, except insofar as concerns the instant invention.

Referring now to the drawings, in which like reference numerals refer to like parts, it will be observed that the general pump assembly comprises` the usual rotor I0 operable in a split lobe casing formed of a lower half Il and an upper half I2. Combination head members and port cones I3 and I4 serve to complete the lobe cas- I0." 'Ihe port sections I6 and I8 extend inwardly of the rotor, from opposite sides thereof, somewhat in the nature of hubs for the rotor,

, and these sections are constructed to form inlet and discharge passages for the pump, and to establish communication between theinlet'connection I9, the outlet connection' 20, and the interior of the lobe casing.

The rotor l0 is keyed at 2| to the drive shaft 22, and is provided with the usual vanes 23 forming displacement chambers or buckets 24 in the customary manner.

When assembled, the sections II and I2 will form a lobe chamber having, in the illustrated embodiment, an upper lobe 25 and a lower lobe 26, said lobes being separated by lands 21 and 28.

From the standpoint of normal pump operation, it will be understood that the rotor with its peripheral displacement chambers, the port cones therefor, and the'lobes and lands of the pump chamber or lobe casing, all co-operate in the conventional manner well understood in the art.

Duplicate bearing assemblies 29 for the drive shaft 22, each incorporating a mechanical seal for the shaft, are mounted in the respective end sections I5 and I1. l

By reference to Fig. 5, it can be seen that the bearing assembly or cartridge comprises a frame or housing 30 which mounts and supports the shaft bearings, exemplified herein as tapered i roller bearings 3|, the inner races of which are held in place by suitable caps 33 surrounding the shaft 22. The mechanical seal for protecting the bearings is exemplified by an annular ring or sealing member 34 at the inner slde of the car' tridge, and a sealing ring; 35, preferably backed up by a packing ring 35- A, which prevents leakage along the shaft and is normally pressed into engagement with thering 34 by a spring36 encircling the shaft 22. The end of the spring 36 remote from therlng 35 bears against a anged ring 31 which in turn is held from sllibage tof wardethe linterior of the pump by .a sliiulder 38 on the shaft 22. In order to accomro'daterany leakage which might occur past the' mechanical A.sealjust described, the bearing-hous'ingf'is cored to form .collecting passages 39 yand 4D either insingle or'multiple arrangement, .and these pasg passages marked "A in Fig.v 5.

ing. The unit I3 is formed with a head or end lIt will be evident. then, lthat the entire assemblage zor bearing cartridge, together with the mefzchanical seal, may be removed -unitarily from the ishaft 22, :and the lobe casing.l To facilitate this removail for replacement, repair, or inspec-v e tion purposes, the .is held in place simply by Sth-e bolts :or screws '42 `which extend through 'a vflange '43 in the housing 30, the housing being .held in place by bolts 44 -detachably threaded to the bolt 42. By removing the bolts 44, it is then a `simple 4matter to slide the entire cartridge off the end offhefshaft.

From the "foregoing, it will be evident that a very simple assemblage of parts has been pro vided, in which the lobe cover or upper section I2 of the casing may be removed at any time to permit inspection of and access to the interior of the pump without requiring the further removal of any essential parts. No gaskets or head bolts have to be removed to take the lobe cover off for inspection, and it has been pointed out that the usual, separable headsor ends of the pump chamber have been done away wi-th, and .f

equally. on each sideof the rotor.

have been replaced by the port cones which are designed for that purpose. The straight part of each cone is formed with a iiange 45, boltedl members, being cylindrical in section; may be slid along-in the lobe structure and held at the proper distance from the rotor by the shims .46.

When the upper half I2 of the casing is removed.

feelers can be put in between the rotor and a port cone -to measure the clearance, and the whole assemblage may be turned over to see that it is free, before the top or cover I2 is replaced and bolted in position. Preferab vno gasket will be provided between the iiange l and the -upper half I2 of the lobe casing. This is to facilitate removal of the head, or the cover I2, without breaking any joints between the port member and the casing section I2. It might be noted at this point that the upper portion I2 of the lobe casing is secured in place simply by the bolts 5l and suitable dowelling, and that Vwhen this section is removed, the interior of the pump may be readily hosed down, if the pump has been used, for example, as an installation in a paper mill wherev pulp or the like might accumulate in the casing.

Adjust-ment of end play in the rotor may be obtained, after the proper total side clearance hasbeen provided by the shirns 6, by shims 55 at each side of the pump, inasmuch as the bearing cone 32 abuts a shoulder 56r on the shaft 22 and is in turn engaged b y the cap or cover 33.- Preferably, the side clearance will be divided vlin manufacture, a shim of known thickness may be placed in the horizontal joint 4l (Figs. 2 and 3) before boring, and thereafter, in assembly, the shims may be removed `and a resilient gasket slightly thicker than `-the shims placed in the joint d1. Subsequently, when the bolts are set. up, this gasket squeezes down, allowing the upper half of the casing to closely grip the cone and make a substantially watertight seal. A thin packing gasket can be used A drain 48 (Fig. 3) may be provided for the bottom ofthe space 69 in the casing, this drain leading into a conduit or passage 50 formed in the upper half of the casing. The passage 503 may be either piped into the inlet of the pump, as indicated at 5l, or separately vented to a drain. Thus, if there is any slight leakage into the chamber or space '39, it will be negligible, and may be led away without showing any drip around the port cones. Such leakage, if. any. will always be liquid, as the joint is at the periphery of the rotor.

In this connection, it might be noted that the interior of the cylindrical part of the cones is connected to the casing on the inlet side through the annular port 52, and on the outlet side through the annular port 53. These connections are between the cones and the bottom half of the casing, and the top halfof the casing, therefore, never has to seal against an air or gas leakage, but yonly against leakage of liquid which may seep 'throughthe casing.

The normal mode of sealing the pump against f leakage is best illustrated in l, and is similar to the method illustrated/in my application,

mentioned above. Sealing liquidsuch as water, is introduced in each end of the pump, through the pipes 51e-51, preferably under a pressure v equal to, or slightly greater, than the discharge pressure of 'the' pump. In this manner, fresh water maybe sent through all clearances, even in A opposition to any pressures-'developed 'in the pump, between the rotor and its casing, and between the rotor and the cones, and this will pre-- vvent fibers or otherforeign matter vwhich may be introduced into the'pump, from lodging in` the. running clearance spaces, as well as sealing such clearance spaces. It also provides fresh water, free from such foreignmatter, around the mechanical seals, and serves to keep these seals cool as well. y .4

The requirements for introduction of sealing liquid, and recirculation thereof when' desired, may' vary with different installations.` Several di'verent examples will be found in my ,Patent No. 2,195,174, above mentioned, and the structure of the instant disclosure lends itself readily to variable conditions.

The base of the pump is partitioned to form a longitudinally extending chamber having an opening 59 in its upper wall effective to establishcommunication with the space 60 behind the head section Il of the combined port and head member I4. An opening 6I in this member establishes communication between the space 60 and the interior of the port member, in general proximity to the mechanical seal about the` shaft of the pump. f

When the sealing liquid is introduced as shown in Fig. 1, the port or opening 59 will be closed by a plug 62 and the port 6I left open. Circulation of the liquid entering/at 5l will then be readily fitted to the various clearances.

In Fig. 4, however, there is shown an alternate construction wherein the chamber 58' is used as a separator, and the sealing liquid recirculated fromthe lower half o f the casing and separator chamber 58 back to the desired points. In this construction the plug 62 is removed, and

a recirculating pipe 63 substituted therefor. The

the pump, while permitting the pump rotor tol continue its rotation. rAn arrangement for accomplishing this unloading and a description of the reasons therefor and attendant advantages form the subject matter of my co-pending agplication, Serial No. 203,169, filed April 20. 1 38.

VThe structure of the present' invention,l as Y shown particularly in Figs. 2 and 6, is designed to incorporate'such an unloading meansand to this'end there are provided ports 66-66 which permit removal of the lsealing liquid, for

unloading purposes, through the chamber 5B. When the unloading arrangement is used, the automatic control valve therefor (not shown) will be placed in the line 61 to operate in accordance with the disclosures of said application. If it is desired to eliminate the automatic unloading feature from an installation, then the port for reception of the line 61 may be plugged, as indicated at l68. Incidentally, the plug 68 permits access to the pump chamber for cleaning or draining purposes.

From the foregoing description, operation and advantages of the improved pump will be evident. The horizontally split casingpermits removal of the top section without disturbing any working parts, thus affording full access to the interior of the pump. Should it be desired to remove either a port section or a head section, this may be simply accomplished, since the port and head sections arecombined as a single unit. The shaft bearings may be removed, either without disturbing the mechanical seal, or as a complete cartridge with which is incorporated the mechanical seal for the bearings. The introduction, circulation, and recirculation of sealing liquid is accomplished with respect to all clearances and points of possible leakage in a manner which provides a flow of fresh liquid which. in addition to sealing, acts to clear and cool the various parts. The entire assemblage is so designed that adjustment may be readily made in a very simple and easy manner.

While the invention has been described herein in connection with a pump having 'a rotor mounted between a pair of conical or cylindrical port members, obviously it is readily applicable to pumps in which the rotor cooperates with but a single port member on one side only thereof, or with a structure embodying more or less than a pair of lobes.

Since the shaft bearings are sealed, in a cartridge form they are readily introduced into the casing where they are cooled by the introduction of sealing liquid, and being combined with a mechanical seal, this seal is likewise protected by the introduction of fresh Water. However, it will be readily apparent that the introduction of the sealed bearings in the pump heads, while an advantageous feature, is not an essential one, since outside supports could be used for the bearings in a manner similar to present day standard construction,

Hence, the embodiments herein are to be construed as illustrative, and not as limiting, other than as defined by the claims appended hereto.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. A pump structure comprising a base, a lobe casing split horizontally to form upper and lower casing sections, a port member extending axially inwardly of said casing, and having a passage communicating with the interior of the casing, said port member having a section shaped, constructed and arranged to provide a casing head, a pump`impe1ler within said casing, said casing head being so proportioned with respect to the cross sectional dimensions of the split casing as to provide, when removed from the assembly, for ready removal of said impeller through the exposed head end of the casing, and means mounting said port member with its 'head sect1on, and upper casing section independently of each other, whereby said upper casing section may be removed while said port member and head section is retained in position.

2. A pump structure comprising a base, a lobe casing split horizontally to form separable casing sections, a port'member extending axially inwardly of said casing, said casing head members co-operative with said separable sections to dene, when' in assembled relation, a pumping chamber, a pump impeller within said chamber, said casing head members being so proportioned with respect to the cross sectional dimensions of the split casing as to provide, when removed from the assembly, for ready removal of said impeller through the exposed head end of the casing, and means to mount said sections and heads detachably in assembled relation such that one of said sections may be removed withouttdisturbing the remaining elements of the assemblage. 1

3. A pump structure comprising a base, a lobe casing split horizontally to form separable casing sections, a port member extending axially inwardly of said casing, said casing head members co-operative with said separable sections to define, when in assembled relation, a pumping chamber, a drive shaft extendable through said casing heads and lobe casing, a rotor on said shaft co-operative with the lobes of said casing to effect a pumping action, one of said casing head members being so proportioned with respect to the diameter of the rotor as to permit, when removed from the assembly, removal of the rotor from the casing, and means to mount.

said sections, heads, shafts and rotor detachably in assembled relation such that one of said sections may be removed Without disturbing the remaining elements of the assemblage.

4. A pump structure comprising aabase, a lobe casing shaped to define upper and lower pumping lobes separated by lands, said casing being horizontally split through the lands to define upper and lower casing sections, port members extending axially inwardly of said casing, to provide passages communicating with the interior of the casing, said port members each having a section shaped, constructed and arranged to form a casing head, a pump impeller within said casing, one of said casing heads being so proportioned with respect to the cross sectional dimensions of the split casing as to provide, when removed from the assembly, for ready removal of said impeller through the exposed head end of the casing, and means mounting said port members and upper casing section independently of each other, whereby saidupper casing' section may be re- ;riioved, and said port members retained in posi- 5. A pump structure comprising a base, a lobe casing split horizontally to form upper and lower casing sections, a pump rotor operable in said casing, a port member extending axially inwardly of said casing and rotor, to provide a passage communicating with the interior of the casing, a drive shaft for said rotor extending through said port memberand rotor, said port member having a section shaped, constructed and arranged to provide a casing head, said casing head being so proportioned with respect to the diameter of the rotor as topermit, when removed from' the assembly, removal of the rotor from the casing, and means mounting said port member with its head section, and upper casing section independently of each other, in assembled relation, whereby said upper casing section may be removed while said port member and head ranged to provide a casing head, said casing head being so proportioned with respect to the diameter of the rotor as to permit, when-removed from the assembly, removal of the rotor from the casing, means mounting said port member with its head section, and upper casing section independently of each other, in assembled |relation, whereby said upper casing section may be removed while said port member and head section, rotor and shaft, aremaintained in assembled relation, and means to adjust said rotor relative to said casing and'port member, when said upper casing section is removed.

y 7. A pump structure comprising a base, a lobe casing split'horizontally to form upper and lower casing sections, a pump 'rotor operable in said casing, a port member extending axially inwardly of said casing and rotor, to provide a passage communicating with the interior of the casing, a drive shaft for said rotor extending through said portmember and rotor, said port member having a section shaped, constructed and arranged to provide a casing head, said casing head being so proportioned with respect to the diameter of the rotor as to permit, when removed from the assembly, removal of the rotor froml the casing, a sealed bearing for said shaft detachably mounted in said casing head section, and means forming part thereof to provide a mechanical seal against leakage around the shaft.

8. A pump structure comprising a base, a lobe casing split horizontally to form upper and lower casing sections, a pump rotor operable in said casing, a port member extending axially inwardly of said casing and rotor,l to provide a passage communicating with the interior of the casing, a drive shaft for said rotor extending through said port member and rotor, said port member having a section shaped, constructed and arranged to providea casing head, said casing head t being so proportioned with respect to the diameter of the rotor as to permit, when removed from the assembly, removal of the rotor from the casing, means positioned substantially axially of said head section to provide a mechanical seal against leakage along the shaft, and means mounting said port member with its head section, shaft, rotor, and mechanical seal inv assembled relation independently of said upper casing section,where by said section may be removed while said other elements are maintained in assembled relation.

` 9. A pump structure comprising a base, a pump casing split horizontally to form separable upper and lower sections, means detachably connecting the upper section to the lower section, means providing casing heads, effective in commotion with said sections, to denne a pumping chamber, a pump impeller in said chamber, and means mounting said heads in the structure independently of said upper section, whereby said upper section may be separated from the casing without disturbing said heads, said heads being of a diameter at least as great as the 'diameter of the impeller whereby to permit removal of the rotor 10. A pump structure comprising a base, a lobe casing split horizontally to form upper and lower sections, a port member vextending axially inwardly of said-casing, said `port member having a section shaped, constructed and arranged to member and head section is retained in position, said head section being of a diameter at least-,as great as the diameter of. the impeller whereby4 to permit removal of the rotor without disturbing said upper and lower'rsections, and to provide ready access to the lobe of the casing.

11. A pump structure comprising a base, a lobe casing split horizontally toform upper and lower casing sections, a pump vrotor operable in said casing. a port member extending axiallyinwardly of said casing and rotor, to provide a passage communicating with the interior of the casing,

v a drive shaft for said rotor extending through said port member and rotor, `said port member having a section shaped, constructed andarranged to provide a casing head, said casing head i being so proportioned with respect to the diameter of the rotor as to permit, when removed from the' assembly, removal of the rotor from' the casing, means mounting said port member with its head section,and upper casing section independently -of each other, in assembled relation, whereby. said upper casing -section may be removed while said port member and head-section, rotor and shaft,l are maintained in assembled relation, and means to introduce and circulate a sealing liquid to clearances between the rotor,

the interior of the casing, and the port member.

12. A pump structure comprising a base, a lobe casing split horizontally to form upper and lower casing sections, a pump rotor operable in said casing, a port member extending axially inwardly of said casing and rotor, to provide a passage communicating with the interior of the casing,

a drive shaft for said rotor extending through said port member 'and rotor, said port member having 'a section shaped, constructed and arranged to provide a casing head, means carried by and positioned substantially axially of said head section to provide a mechanical seal against leakage along the shaft, means mounting said port member with its head section, shaft, rotor, and mechanical seal in 'assembled relation independently of said upper casing section, whereby said section may be removed while 4said other elements are maintained in assembled relation, and means to introduce a sealing'lquid in proximity to said mechanical seal, under pressure at leastequal to the discharge pressure of the pump, whereby to seal running clearances between the rotor and the port member and casing and to maintain said mechanical seal free of deposits of materials in the pump.

13. A pump structure comprising a base, a lobe casing split horizontally to form upper andlower casing sections, a pump rotor operable in said casing, a port member extending axially inwardly of said casing and rotor, to provide a passage communicating with the interior of the casing, a drive shaft for said rotor extending through said port member and rotor, said port member having a section shaped, constructed and arranged to provide a casing head, a sealed bearingv for said shaft detachably mounted in said without disturbing said upper and lower sections. l

I casing head section, means forming part thereof to provide a mechanical seal against leakage around the shaft, and means to introduce 'a sealing liquid in proximity to said bearing and mechanical seal unit to cool the same, and thereafter seal running clearances between the rotor and port member. A

14. A pump structure comprising a base, a lobe casing split horizontally to form upper and lower casing sections, a pump rotor operable in said casing, a port member extending axially inwardly of said casing and rotor, to provide a passage communicating with the interior of the casing, a drive shaft for said rotor extending through said port member and rotor, said port member having a section shaped, constructed and arranged to provide a casing head, means mounting said port member with its head section, and upper casing section independently of each other, in assembled relation, whereby said upper casing section may be removed while said port member and head section, rotor and shaft, are maintained in assembled relation, means to introduce and circulate a sealing liquid to clearances between the rotor, the interior of the casing, and the port member, a separating chamber in said casing, and means to recirculate the sealing liquid through said separating cnamber and casing.

15. A pump of the class using liquid initsl pumping action comprising a stator, a rotor operable therein and a drive shaft for said rotor,

said stator having a base defining the lower halt" of a lobe casing, a separable cover therefor delining the upper half of said lobe casing, said cover being mounted for removal, and assemblyl with respect to said base, freely and independently of the remainder of the pump structure, and means in said cover to collect and drain seepage` from the interior` of the pump.

16. A pump structure comprising a base, a lobe casing split horizontally to form upper and lower casing sections, a pump rotor operable in said casing, a port member extending axially inwardly of said casing and rotor, tov provide a passage communicating with the interior of the casing, a drive shaft for said rotor extending through said port member and rotor, said port member having a section shaped, constructed and arranged to provide a casing head, said casing head being so proportioned with respect to the diameter of the rotor as to permit, when removed from the assembly, removal of the rotor from the casing, means mounting said port member with its head section, and upper casing section independently of each other, in assembled relation, whereby said upper casing section maybe removed while said port member and head section,rotor and shaft, are maintained in assembled relation, and means to adjust said port member axially of the casing, to accommodate wear, when said upper casing section is remove 17. i A pump structure comprising a base, a lobe casing split horizontally to form upper and lower casing sections, a pump rotor operable in said casing, a port member extending axially inwardly of said casing and rotor, to provide a passage communicating, with the interior of the casing, a drive shaft for said rotor extending through said port member and rotor, said port member having a section shaped, constructed and arranged to provide a casing head, said casing head being so proportioned with respect to the diameter of the rotor as to permit, when removed from the assembly, removal of the rotor from the casing, means mounting` said port member with its head section, and upper casing section independently of each other, in assembled relation, `whereby said upper casing section may be removed while said port member and head section, rotor and shaft, are maintained. in assembled relation, and means to adjust said port member axially with respect to said rotor.

18. In a liquid ring pump, a horizontally split lobe casing, a rotor therefor, head members for said casing each having a diameter at least as IRVING C. JENNINGS. 

